RH033 Exam Dumps : Red Hat Linux Essentials

The /etc/profile shell script is the first startup script run when a login shell is started. It runs only for the login shell.

What is a Login shell?

A login shell is a shell that is started by login into the system. The login shells' responsibility is to start the non-login shell

and to make sure that environment variables are set so as to ensure that a user can get all the default parameters needed at start-up.

Login shell will set the PATH environment variable, TERM, the UID and GID of the terminal amongst other things. These are the requirements in order to work proficiently. Additionally, the login-shell will set default variable such as USERNAME,

HISTSIZE, HOSTNAME, HOME, etc.

Answer option A is incorrect. The ~/.bashrc shell script is the first startup script run when a non-login shell is started.

A non-login shell is a shell started by a user or a program issuing the bash command.

Some non-login shells are as follows:

su

graphical terminals

executed scripts

any other bash instances

Answer options D and B are incorrect. The non-login shells first call ~/.bashrc. The ~/.bashrc calls

/etc/bashrc, and then /etc/bashrc

calls /etc/profile.d.

The bg utility resumes suspended jobs from the current environment by running them as background jobs if job control is enabled. If the job specified by job_id is already a running background job, the bg utility will have no effect and shall exit successfully. Using bg to place a job into the background will cause its process ID to become "known in the current shell execution environment", as if it had been started as an asynchronous list.

Answer option D is incorrect. The fg utility continues a stopped job by running it in the foreground, some shells are not able to run this command.

Syntax:

fg [%job] Where %job specifies the job that a user wants to run in the foreground.

Answer option A is incorrect. The jobs command lists the jobs that are running in the background and in the foreground. If the prompt is returned with no information, no jobs are present.

Syntax: jobs [-p | -l] [-n] [-p] [-x] [job id]

Some important options used with jobs command are as follows:

Answer option C is incorrect. The top command is used to produce a frequently-updated list of processes. By default, the processes are ordered by percentage of CPU usage, with only the "top" CPU consumers shown. This command shows how much processing power and memory are being used, as well as other information about the running processes. The following figure demonstrates the output of the top command:

Ctrl-w key-combination with an arrow key is used to jump from one window to another. This will move you to the next window in whichever direction the arrow would normally move your cursor. Instead of the arrow keys, you can also use

vi's traditional h, j, k and l keys for the same effect.

Answer options B and A are incorrect. Ctrl-w, s and Ctrl-w, v key-combinations are used to view a file in two windows in a single vim screen.

Ctrl-w, s splits the screen horizontally and Ctrl-w, v splits the screen vertically.

Answer option D is incorrect. Ctrl-w, q is used to quit from your current window.